Dam and drive across Nant Meigan on Baron Hill estate

Monumental masonry dam closing the head of Nant y felin and impounding the stream for industrial and picturesque purposes. Coursed and random masonry (approx 14m high) with heavily battered profile and four large raked buttresses. At mid-height level, there is a segmentally-arched and brick-vaulted tunnel with projecting stone sill to the main water outlet with ramped spillway between the buttresses. Low down to right is a second outfall under a long (now split) lintel which formerly fed the stone-lined leat running downhill to the former slate dressing mill (rebuilt in 1675). Driveway is carried on top with pond to upper side of dam and then continues N to bridge over B5109 and the ruins of Baron Hill beyond.